1. Field of the Invention
The present invention relates to a method of monitoring the movements of an individual in and around buildings, rooms, and other spaces, and then particularly to a method of enabling the movements of individuals to be monitored during military or civilian exercises. More particularly, the invention is concerned with indicating the direction in which an individual faces, and to show this direction and also to show the direction in which a weapon that might be carried by the individual is directed. The invention also relates to a direction indicator, which is adapted for use with the inventive method and also with other applications in which such a direction indicator can be used.
2. Description of Related Art
WO 02/075352 A1 teaches a method of the kind mentioned in the introduction, in which each individual carries a passive transponder that includes an individual-unique identity for co-action with an active antenna which is connected, either directly or indirectly, to a monitoring centre for the transfer of signals received from the transponder, and where a plurality of antennas are dispersed in and around said buildings, rooms or the like to be monitored, wherein the signals transferred to the monitoring centre are used to show movements of individuals on a display screen, or monitor, in the form of a three-dimensional animated picture.
National special forces, special police, etc., are trained for battle/special missions in built-up areas. These missions are, in reality, extremely difficult and risky, since an attacker or terrorist may have installed booby traps in the buildings, ships, aircraft or corresponding places in which the missions are carried out. Moreover, these missions or operations are often carried out in the dark. The attack on/or storming of a building, room, or the like, is effected, inter alia, with the assistance of smoke/flash grenades and backup fire. Training of soldiers, police, etc., in respect of such missions, and the study of the behaviour and the movements of said soldiers, police, etc., are extremely difficult. It is important that the leader of the exercise is able to monitor certain behaviours of the individuals taking part in the exercise, for instance the direction in which an individual points his/her weapon during certain moments of the exercise, the direction in which the individual is looking, whether the individual advances into a space, or walks backwards. It is highly essential that the leader of an exercise is able to obtain answers to these questions, and may well be a life or death issue in the case of a real mission.
One problem with this known method is that it has not been possible in an animated display to illustrate in which direction an individual faces, or in which direction the weapon is pointed, owing to the fact that there is no technical equipment that can be used to this end.
A number of different types of direction indicating devices are available. One type of device is a “typical” mechanical needle-equipped compass with which it is possible to read a course/direction in the horizontal plane, although not in the vertical plane. Another type of direction indicating device is an electronic device in which the vertical direction can be shown, in addition to a horizontal direction. These horizontal and vertical directions are shown on a display. One drawback with such electronic compasses, however, is that when spun rapidly through a full revolution several times, the compasses loses their position and direction and must be stopped so as to allow time for calibration.
Another drawback with the types of compass mentioned above is that they cannot be read by some other person or by hardware from long distances. Although it is possible to see the direction of individuals and objects in motion with the aid of radar or GPS, this possibility is based solely on the assumption that said individuals/objects are moving in a forward direction. Radar and GPS, however, provide no possibility of determining the direction in which an individual or an object, e.g., a weapon, faces when the individual/object is stationary.